PAPE1~S AND PROCEEDINGS OF THE ROYAL SOCIETY OF TASMANIA, VOLUME 96

ON THE NOMENCLATURE PTERUCHUS JOHNSTONI (FEISTMANTEL) COM. NOV.

By

JOHN A. TOWNROW.

Department of Botany, University of Tasmania.

(With one figlu'e.)

heads, preserved sporangial surface uppermost. ABSTRACT Diameter (including projecting pollen sacs) about The holotype of the species hitherto called 5 mm. (largest 8 x 6 mm.). Pollen sacs very close pteruchus ajricanus Thomas is redescnbed and set, at least 30 per head, about 2 mm. long and refigured; on grounds of priority this sp~cies must 1 mm. wide, slightly inflated, apex bluntly pointed now be called pteruchus johnstom (Felstman~el) dehiscing by a longitudinal s,Ut flanked by narro"'; com. nov. The specimen named Stachy?pltys cells. Rachis showing imprints of cells comprising annularioides Shirley is redescribed and consIdered a wing of narrow cells (about 150,u x 35,u) , and a to be identical with P. johnstoni. central band of wider cells with stomata, measuring about 180,u x 701~. Pollen sac impressions showing imprints of elongwted cells about 250 M x 74 M . No INTRODUCTION. cuticle or pollen preserved. The type species of the genus pteruchus has This specimen was first flgured by Johnston hitherto been called Pternchus ajricanus Thomas (1888), but he did not give a name, believing it to (1933), but Thomas and others (Jones and de Jers~y be attached to a specimen of the leaf Czekanows7cia 1947 Townrow 1961) have pointed out that certam (originally Baiera) tennifolia. Feistmanted (890) specimens desc'ribed earlier might be identical ,wit? gives an~ther figure and also a name, Trichopitys P. ajricanus, and if so, that the earlIest of Lhelr Johnstonz. He also believed the pollen organ and names might have priority. These speClmens are leaf to be attached. Walkom (1924) pointed out as follows:- that the leaf and pollen organ are not joined but he accepted the view that they belong to th~ 1. Sphenolepis rhaetica Geinitz, 1876, p. 12, pI. same plant and he alsoO l'evertedto Johnston's 2 figs. 23, 24. (Location of specimen un­ nomenclature, known.) 2. "Male flower of Baiera tennijoZia" John­ Walkom yvas correct; the leaf and pollen organ ston, 1888, pI. 27 figs. 2D and E (see also are not J0111ed. They not only lie at different Feistmantel, 1890, p. 113, pI. 10, fig. 5; levels in the rock but point in opposite directions, and Walkom, 1924, pp. 85-86, figs. 15, 16). see fl~. lA. There are, indeed, no grounds except (Tasmanian Museum: No. B 1049,) aSSOCIation for believing that the two fossils have 3. Stachyopitys annularioides Shirley, 1898. anything to do with one another. The leaf itself p. 13, pl. 18, fig. 1. (Geological Survey of I c~nnot identify ... It probably is C. tenuijolia, but It could be a speCImen of Xylopteris (older name Queensland: No. F. 142,) ?tenopteris) elongata, which is probably present Thanks to the kindness of the Director, the Tas­ 111 the Lord's Hill locality (see Johnston 1888 manian Museum, and the the Government Geolo­ pI. 27, flg. 7). ' , gist, Geological Survey of ~ueensland,. I h~ve been Specimen B 1049 agrees in every available able to examine Johnston s and ShIrley s specI- fe.ature, including such cellular detail as is visible. mens. wlth better preserved material called pteruchus ajricanus, and differs distinctly from the other two Geinitz's specimen is indeterminable from his species, P. dubius and P. sirnrnondsi. It is therefore figure. Until the specimen is re-examined his name identifled. Feistma,ntel's name is the earliest given Sphenolepis rhaetica must be wn~ten oft' .as a to the pollen organ as such, and therefore becomes nomen vanum., a name applied to an mdetermmable the specific name for the species, and ,the specimen type. B 1049 becomes the holotype. The record has additional interest in that it is DESCRIPTION AND DISCUSSION another record of association between Pteruchus (D Johnston's specimen: Tasmanian Musenm j?hnst.oni and the leaf Dicroidium odontopteroides, B 1049. Sporophyll 2.5 ems. long, base not seen, S111ce It has been suggested (Townrow 1961) that rachis maximum width 2 mm., four alternate these two fossils are parts of the ~arne plant pinnae present, but no vegetative pinnules. Pinn,ae p. odontopteroides is recorded from Lord's Hill, and expanding into more or less round sporangIal IS present on B 1049. 91 92 ON TI-LE NOMENCLATURE OF PTERUCHUS JOHNSTON! (FEISTMANTEL) COM. NOV.

(ii) Shirley's specimen: Geological Survey oj 1890 Trichopitys johnstoni Feistmantel, p. 113, Queensland F 142. This specimen which lacks a pI. 10, fig. 5. (Johston's specimen refigured,) counterpart and is an impression only, shows the 1898 Stachyopitys annulariodies Shirley, p. 13, remains of at least two sporophylls. The surface pI. 18, fig. 1. of the fossil is very uneven, and I think there is 1933 pteruchus africanus Thomas, pp. 235-237, little doubt that the specimen has split through the pI. 24, figs. 71, 72, text-figs. 34, 35. plant material (or the space left by its absence) 1961 pteruchus ajricanus Thomas: Townrow, pp. leaving about equal quantities on part and counter 293-296,pJ. 24, fig. 4, pl. 25,figs. 1, 2, pl. 26, figs. part, though in the absence of the counterpart 2, 4-11; text figs. 1-3, 6-10, this cannot be confirmed. No sporangial heads are (DiagnOSIS and full synonomy given.) complete, the most complete show the remains of Holotype: Tasmanian Museum B 1049. about 25 pollen sacs, so the original number was Locality: Lord's Hill, Hobart, Tasmania. probably greater than this. Horizon and Age: Feldspathic Sandstone Series, The number of pollen sacs is an important point, Triassic. for the only definite difference between P. johnstoni Collector: R. M. Johnston, in about 1880. and P. annularioides is that the latter was suposed Emended Diagnosis. Microsporophyll about 2 to have fewer pollen saes per head. It now appears ems. long', rachis about 1.5 mm. wide at base. About the number of pollen sacs is about the same. eight (4-9) long, normally unbranched pinnae In dimensions, in showing the cast of a strongly present. Heads round to about four times as long rugose non-sporangial surface of the head, and so as wide, width about 5 mm., non-sporangial surface far as visible, in size and form of the cellular strongly rugose, about 10 lobes per head, lobes impressions, this specimen agrees with the holotype small in propor'tion to size of head. Pollen sa,cs of P. johns toni, and is united with it, the name 30 or more per head, about 2.5 mm. long and 1.5 annularioides becoming a synonym. Besides Shir­ mm. wide. Cell outlines faint, 11" or less, sinuosities ley's specimen only two other fossils have been small, sometimes absent, about 11" long, usually called pteruchus (or Stachyopitys) annularioides. obtuse, not pointed. Stomata somewhat sunken, They are in Jones and de Jersey (1947) text-fig. 38, poles exposed, pit not overlapped by cutin fianges. which is hardly identifiable, and in Halle (1913), Pollen bisaccate, corpus normally deeper than wide, pI. 6, figs. 13, 13a, which is probably distinct. rarely rounded (polar view). Aposaccale areas (polar view) obtuse or bluntly pointed, grain as high as wide, or higher, outline trapezoid. Cappa con­ CITATION AND HOLOTYPE vex, other surfaces more or less flat. Roots of sacci markedly offset distally, proximal roots normally 1888 Male fiower of Baiera tenuifolia Johnston, inserted distally to widest part of corpus. Sacci pI. 27, figs. 2D and E (figs. 2C and 2B distinct) . as deep as corpus, or a little less, often slightly .:\

B

A

LEGEND FOR FIGURES. A. The h110type B 1049. Tasmanian Museurn. X 2-5. B. Imprints of cells and stomata from the rachis B l049jX 120. C. Imprints of cells and the dehiscena slit on a sporangiun1 B 1049 X 120. JOHN A. TOWNROW 93

Infiated. Ornament on sacci: brochi ca. 3/1 in HALLF., T. G .• 1913.~The MesO'zoic flora o£ Graham Land. W£8S. diameter, muri ca 10 wide. Cappa normally slightly Rrgeb. Schwed. Sild]Jol. EX]Jcd., 3 (14): 1-13. JOHNS'fON, R. M., 18Sg. -~The Geology of Tasmania, Governme'nt uneven, sometimes thickened (up to ca 2,u.). Dimen­ Printer, Hobart. sions (fiducial limits bracketed): corpus depth O. DB .JBH8EY, N .•r., 1947.-The flora of 45.30 (3.56). width 32.2/1 (3.70); width of total MeasUreS-YllO'rphology and floral grain 62/h (3,51); height, of sacci 35,50 (1.88). geol. de]). paps., n.s. 8: 1-88, SHIRLJEY, J'J to the fossil flora of Queensland. BulL : 25 t- v. THOMAS, H. HAMSIIAV\T, 198:3."-On SOIne pteridospermous plants frOIn the Mesozoic rocks of StJ'uth Africa. PhU. 'r'rans. TOY. References Soc. Lond., B 222:: 19:1-254. TOWN ROW, J. A., 19GL,·~On PteruchB the miel~c;sporophyll of the Fl!;lSTMANTEL, 0., 1890.-Uhlosne utvary v Tamnanii. SIJiS. Jub. Corystospermaceae. Bull. Brit. ~7l1us. (nat. lu:st.) geol. Cesk. Spaiee. N auk., I: 162 + x. 6 : 285--316. GEIKITZ, 1-1. n., 1876.-Ueber y-haetische Pflanzen-und Thierreste WALKOM, A. B., 192',11.--Notes of some Tasmanian Mesozoic in den argentininsehen Provinzen La Rioja, San Juan llnd Plants. Part 1. P(tp. PrOG. TOy. Soc. Tas., voL for .1924: Mendoza.. Palaeonto.QrnlJh ..• suppl. 8, abL 2: 1-14. 73-89.